Rack and Pinion Path Blocking for Compact Media Feeders

Solution Overview

Problem

Existing medium feeders for recording apparatuses, such as printers, face challenges in maintaining a compact height dimension while allowing for a sufficient number of media to be loaded, as they require additional space for rotating components like cams and followers, which limits the tray's capacity.

Innovation Solution

A medium feeder design incorporating a tray, a feeding roller, a guide member, a path blocking member, and a switching unit with a rack and pinion gear mechanism that allows the path blocking member to switch between blocking and open states without increasing the apparatus height, enabling efficient media guidance and preventing media collapse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a rotating cam and cam follower mechanism is used to switch the path blocking member, then the path blocking member can be switched between blocking and open states, but the apparatus height increases and the media loading capacity decreases

Engineering Contradiction:

Improvepath blocking member switchingVSAvoidapparatus height

Core Design Contradiction:

Ease of operationVSLength of stationary object

Solution Approach 1:

The patent changes the switching mechanism from a vertical rotation motion (cam and follower) to a horizontal linear motion (rack and pinion). The rack moves horizontally along the feed direction to switch the path blocking member, eliminating the need for vertical space and reducing apparatus height while maintaining the switching function.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Instead of using a vertical cam rotation mechanism that requires space above the tray, the patent inverts the approach by using a horizontal rack displacement mechanism that operates in the feed direction. This inversion of the motion direction eliminates the height increase problem while achieving the same path blocking member switching function.

Inventive Principle:

Principle #13The other way round (Inversion)

2Ease of operation

If a rotating cam and cam follower mechanism is used to switch the path blocking member, then the path blocking member can be switched between blocking and open states, but the number of media sheets that can be loaded in the tray decreases

Engineering Contradiction:

Improvepath blocking member switchingVSAvoidmedia loading capacity

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

The patent changes the switching mechanism from a vertical rotation motion (cam and follower) to a horizontal linear motion (rack and pinion). The rack moves horizontally along the feed direction to switch the path blocking member, eliminating the need for vertical space and reducing apparatus height while maintaining the switching function.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Instead of using a vertical cam rotation mechanism that requires space above the tray, the patent inverts the approach by using a horizontal rack displacement mechanism that operates in the feed direction. This inversion of the motion direction eliminates the height increase problem while achieving the same path blocking member switching function.

Inventive Principle:

Principle #13The other way round (Inversion)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration prevents an increase in apparatus height and maintains a higher media loading capacity by using a rack and pinion gear system to switch the path blocking member, ensuring efficient media feeding and preventing media collapse during operation.

Implementation Method 1

the switching unit includes a rack configured to be displaced in a feeding direction in which a medium is fed from the tray to thereby perform switching of the path blocking member, and a pinion gear that drives the rack

Methodology Applied

Scientific EffectRack and pinion mechanism: Rack and Pinion

Data Source

PatentUS12024385B2Medium transport device and recording apparatus

Publication Date: 2024.07.02 SEIKO EPSON CORP

AI summary

A medium feeder includes: a path blocking member configured to rotate to switch between a blocking state that blocks a feed path for a medium fed out from a tray at a position of the guide member, and an open state that opens the feed path; and a switching unit that performs switching of the path blocking member, wherein the switching unit includes a rack configured to be displaced in a feeding direction in which a medium is fed from the tray to thereby perform switching of the path blocking member, and a pinion gear that drives the rack.